Gong Zhenfeng, Wu Guojie, Xing Jiawei, Wu Xue, Mei Liang
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China.
School of Dalian University of Technology and Belarusian State University Joint Institute, Dalian University of Technology, Dalian, Liaoning 116024, China.
Anal Chem. 2024 Sep 17;96(37):15008-15013. doi: 10.1021/acs.analchem.4c03227. Epub 2024 Aug 30.
Conventional cantilever-enhanced photoacoustic spectroscopy (CEPAS) usually requires the cantilever to be in contact with the gas, which limits its application in dusty and corrosive gas sensing. To overcome this challenge, this paper proposes noncontact fiber-optic cantilever-enhanced photoacoustic spectroscopy (NCFO-CEPAS) for high-sensitivity trace gas analysis. A polyethylene film with corrosion-resistant properties is affixed to the end of the cantilever acoustic sensor, and the effect of the distance between the polyethylene film and the cantilever acoustic sensor on the sensitivity of the system is analyzed by finite element analysis. Compared to the conventional CEPAS, NCFO-CEPAS has a lower background noise deviation. Besides, the potential damage to the silicon cantilever beam by corrosive gases can be avoided as the gas to be measured is not in contact with the silicon cantilever beam, and the gap of the cantilever beam will not be blocked in a high dust environment. Experimental results show that the detection limit of CH gas is 0.5 ppm, and the normalized noise equivalent absorption coefficient reaches 5.93 × 10 cm W Hz. The NCFO-CEPAS technique has the advantages of noncontact remote gas monitoring, not being corroded by gases, and high resistance to electromagnetic interference.
传统的悬臂增强光声光谱法（CEPAS）通常要求悬臂与气体接触，这限制了其在含尘和腐蚀性气体传感中的应用。为了克服这一挑战，本文提出了用于高灵敏度痕量气体分析的非接触式光纤悬臂增强光声光谱法（NCFO-CEPAS）。将具有耐腐蚀性能的聚乙烯薄膜粘贴在悬臂声学传感器的末端，并通过有限元分析研究了聚乙烯薄膜与悬臂声学传感器之间的距离对系统灵敏度的影响。与传统的CEPAS相比，NCFO-CEPAS具有更低的背景噪声偏差。此外，由于待测气体不与硅悬臂梁接触，可避免腐蚀性气体对硅悬臂梁造成潜在损坏，并且在高粉尘环境中悬臂梁的间隙不会被堵塞。实验结果表明，CH气体的检测限为0.5 ppm，归一化噪声等效吸收系数达到5.93×10 cm W Hz。NCFO-CEPAS技术具有非接触式远程气体监测、不受气体腐蚀和抗电磁干扰能力强等优点。
